Description OptiVISOR® lenses are manufactured from high quality optical glass prepared to ophthalmic standards. Sold individually. Item Number Focal Length Magnification DA-2 20″ 1.5x DA-3 14″ 1.75x DA-4 10″ 2x DA-5 8″ 2.5x DA-7 6″ 2.75x DA-10 4″ 3.5x
